Best way to whiten yellowed keys?

[ksd5]

The keys on my 'board have yellowed. They're printed with pad printing. How would I go about whitening them?

I've read that bleach and hydrogen peroxide are good cleaners, but I don't want to damage the lettering.

[washuai]

Search is your friend:  http://geekhack.org/showwiki.php?title=Island:9099.

Actually, I confess, I cheat, I used google.

[iMav]

Search is your friend:  http://geekhack.org/showwiki.php?title=Island:9099.

Actually, I confess, I cheat, I used google.

Google + site:geekhack.org is your friend.  

[AndrewZorn]

i heard the denture cleaners work too

[ch_123]

The keys on my 'board have yellowed. They're printed with pad printing. How would I go about whitening them?

I've read that bleach and hydrogen peroxide are good cleaners, but I don't want to damage the lettering.

Do some searches for "Retrobrite"

[InSanCen]

Do some searches for "Retrobrite"

Yup, works very well.

http://www.psfk.com/wp-content/uploads/2009/03/after_eight_hours.jpg

Not mine, but illustrates what it can do.

[itlnstln]

Toothpaste works pretty well, but I would watch out for the pad printing.  When it comes down to it, pretty much all whitening approaches achieve their goal by removing/eroding the yellowed layer of plastic.  There is some bleaching involved, but you will be wearing away some plastic.  Because of this, just about any approach you use will put the pad printing at risk.